Hello readers and welcome back to our Project Management series. In this article we will be looking at the causes of bottlenecks in projects and how to handle and avoid them in project situations.

The term “bottleneck” as used in project and operations management was coined literally from the neck of the traditional bottle. The neck of a bottle is its narrowest part, and it reduces the pressure and flow of liquid out of it. In project and operations management, the term is therefore used to describe any point of congestion within an organizational system that hinders the flow of work across the various processes that make up the system.

Fig 1. A typical bottleneck

Just like the traditional neck of a bottle, a bottleneck in business is a point in a system where the inflow of workload is greater than the processing capacity of the workstation, thus holding up progress. In simple terms, it is a resource whose capacity is lower than the demand placed on it. The inefficiency caused by the workstation leads to a lot of work in progress, queues and increase in the overall project life cycle time and project cost.

Bottlenecks are often assumed to be a manufacturing issue, and little or no attention is often paid to studying and resolving bottleneck situations in service organizations. The truth remains that, although it is easier to identify bottlenecks within manufacturing organizations when compared to service organizations, a bottleneck is one of the primary causes of project failure and should not be neglected.

Bottlenecks are identified by a detailed analysis of the processes involved within the organization (system). According to Anderson (1999), a process analysis is a logical series of related transactions that converts input to results or output. The analysis helps identify the processes that are not efficient, after which a solution can be provided in eliminating the bottleneck.

In this article we will analyze:

  1. The main causes of bottlenecks in projects
  2. The effect of bottlenecks on a project
  3. How to avoid or handle a project with a bottleneck

For the purpose of this article, we will be using two organizations as examples. The first is a manufacturing setting while the other is a service organization.

Organization 1.

James Heller Cabinet Production Company has various units but among them, the manufacturing unit is the most important unit since it is the core of the business. Once the production drawing has been handed down from the design unit to the manufacturing unit, the production of a standard cabinet is divided into five major processes:

  • Cutting – circular machine
  • Molding – spindle machine
  • Edge binding – edge binding machine
  • Spraying – spraying machine
  • Packaging – manual

Organization 2.

Boniface Consulting is an architectural consulting outfit based in five countries in western Africa. Boniface focuses on the design of commercial buildings and the following are the design processes involved in developing their building designs:

  • Marketing
  • Interpreting customers brief
  • Checking government regulations in the proposed building site
  • Creating initial concept and sketch
  • Developing presentation drawings (three-dimensional drawings and model)
  • Clients approval and changes
  • Adjusting initial design to meet client’s changes
  • Production of working drawings
  • Developing building model


As mentioned earlier, bottlenecks are known to resist process flows within projects and are caused by a lot of factors. Below are some of the primary causes of bottlenecks in projects. It is important to note that this list is not exhaustive as there are other factors not included here.

Resource inefficiency

Efficiency is generally related to the rate at which time, effort and cost is properly utilized when undertaking a task. A resource, which can be a machine or a human, is said to be inefficient when its output is below the universally accepted rate of production (optimal output) of the resource.

For example, the circular machine in James Heller is able to cut 198 pieces of wood every hour, which is then passed on to the spindle machine for molding. If a spindle machine in James Heller has the ability to put molds on 250 pieces of wood per hour at optimum efficiency, but for some reason it can only put molds on 172 pieces of wood, then the spindle machine is inefficient, thus creating a bottleneck. This means that there would be an excess of 26 pieces of wood every hour, or 208 pieces in an 8 hour working day.

Outdated technology

When technologies are not updated, it becomes difficult for organizations to keep up with industry growth. Most organizations then start working the outdated resources harder, which often leads to bottlenecks within the project execution.

Using the same example earlier used, let’s assume the organization decides to upgrade its machines in phases starting with the circular machine and increases the output of the circular machine to cut 400 pieces of wood per hour, while the spindle and the others perform at 100% efficiency. Due to the outdated technology of the spindle machine, even with 100% efficiency (250 molds) it still would not be able to process the output from the circular machine when the circular machine is at 100% efficiency.

Lack of resources

While we have explored how inefficiency and the outdated technology of a resource can lead to bottlenecks, lack of a necessary resource would definitely lead to a bottleneck.

Using Boniface Consulting as an example, let’s assume they have a commission to design a memorial cathedral for those who lost their lives in the September 11, 2001 bomb blast. While the work was ongoing and just before the sketch design phase, the 3D artist decides to resign. Due to the high technicality and skill required for 3D drawings, it’s difficult to get a replacement immediately.

The lack of resource to carry out the task has therefore caused a bottleneck, which would affect the other parts of the project. This would most likely affect the project cost and time.

Improper communication

In Project Communication Management, we saw that proper communication is necessary for the success of any project. If we can all recall, a project manager spends about 90% of his time communicating during a project. Lack of communication or improper communication between resources or resource managers can lead to bottlenecks in a project.

For example, the edge-binding machine in James Heller is broken, which makes it produce at 50% output for 3 days. Lack of proper communication between the managers of these resources can result in the managers of the circular and spindle machines working at 100% efficiency and therefore create a bottleneck at the edge-binding machine.

This is also applicable to the service industry. A good example is when communication between the marketing department and the design unit of Boniface Consulting is not properly synchronized. The marketing unit would go outsourcing for jobs that are beyond the capacity of the design team. The lack of communication would create a bottleneck especially when there are more jobs than the design team can accomplish.


The causes of bottlenecks are not always avoidable and there are situations where there is little we can do about it. Machine breakdowns, staff members falling sick, or unforeseen situations, such power outages, accidents and storms, can sometimes cause bottlenecks. As a good project manager, these breakdowns and unforeseen circumstances should have been planned for in risk management.

Poor maintenance schedule

We can all agree that the lack of maintenance culture is detrimental to the growth and success of any organization. Maintenance often includes the performance of routing action that helps keep a resource in proper working condition. Lack of a proper maintenance culture would lead to unplanned breakdown, which causes bottlenecks as discussed earlier.

Now that we know that the lack of maintenance is bad, can maintenance itself also be bad? The answer is YES. Maintenance can be bad when the timing is not right. While a maintenance culture is great, proper timing and schedule of maintenance activities is as important as the maintenance activity itself.

Maintenance activities should be scheduled for a time when it would not disrupt the flow of processes within organizations. Organizations that run a weekly program can schedule maintenance for weekends. Organizations that run during the day can schedule maintenance for the night period. Projects that run 24 hours can schedule maintenance of their resource during resource shifts.

Interruption of existing process relationships would lead to bottlenecks, but they can be reduced or minimized by avoiding or reducing the amount of unplanned maintenance during a project life cycle.


In this article, we were able to describe the origin of the word bottleneck and how it applies to project organizations today. While we set out to explore the causes of bottlenecks and how to prevent it in projects, we were only able to explore the former. In our next article, we will explore the latter.

That’s all we have for today and once again thank you for reading. Do not forget to drop your thoughts and questions in the comments section.


  1. Project management body of knowledge (PMBOK)
  2. Wikipedia
  3. Adler, P. S., Mandelbaum, A., Nguyen, V., & Schwerer, E. (1995). From project to process management: an empirically-based framework for analyzing product development time. Management Science